Radio Frequency Plasma Spark Plug Development and Engine Testing: Design of a quarter-wave coaxial cavity resonator for use as an ignition source for an internal combustion engine

The Quarter Wave Coaxial Cavity Resonator (QWCCR) plasma igniter is designed, from requirements drawn from previous theoretical work, as an ignition source for an internal combustion engine. The present research has explored the implementation of the QWCCR into an IC engine. The QWCCR design parameters of inner conductor length, loop geometry, and loop position were varied for two igniters of differing operating frequency. Variations of the QWCCR RF parameters as a function of engine geometry were studied by placing the igniter in a combustion chamber and manually varying the crank position. Three identical igniters were fitted with dielectric inserts and the parameters were studied before and after ignition was sustained in a Briggs and Stratton® V-Twin engine. Optimal resonator geometries were determined. RF parameter invariance was found with respect to crank angle and piston distance. The first successful IC engine ignition using a QWCCR was achieved.